Marine conductor pipe assembly



Feb. 11, 1969 R. c. VISSER 3,426,843

MARINE CONDUCTOR PIPE ASSEMBLY Filed 001,. 10, 1966 Sheet 0f 4 INVENTORZROBERT C. V SSER HIS ATTORNEY Feb. 11, 1969 R. c. VISSER MARINECONDUCTOR PIPE ASSEMBLY Filed Oct. 10, 1966 FIG. 2B

' INVENTOR ROBERT c. VISSER ATTORNEY FIG. 2A

Feb. 11, 1969 R. c. VISSER I 3,425,843

MARINE CONDUCTOR PIPE ASSEMBLY Filed on. 10, 1966, Sheet 5 of 4 4 n 4560 330 4o 39 A lh e2 62 540 l FIG. 3

INVENTORZ ROBERT C. VI SSER HIS ATTORNEY Feb 11, 1969 Filed OGt. 10,1966 F IG. 5

F l G. 6

I NVENTORI ROBERT C. VISSER BY: WW

H IS ATTORNEY United States Patent 3,426,843 MARINE CONDUCTOR PIPEASSEMBLY Robert C. Visser, San Dimas, Califi, assignor to Shell OilCompany, New York, N.Y., a corporation of Delaware Filed Oct. 10, 1966,Ser. No. 585,645 US. Cl. 166-.5 Int. Cl. E21!) 43/0]; F16] 55/00 5Claims ABSTRACT OF THE DISCLOSURE This invention relates to apparatusfor use in drilling, completing and working-over operations in oil andgas wells at offshore locations. More particularly, this inventionpertains to fluid conduit apparatus for the control of wellheadappurtenances located at or near the bottom of a body of water.

In an attempt to locate new oil fields, an increasing amount of welldrilling has been conducted at offshore locations, such, for example, asoff the coasts of Louisiana, Texas and California. As a general rule,the strings of casing in a well, together with the tubing string orstrings, extend to a point above the surface of the water where they areclosed in a conventional manner that is used on land wells, with aconventional wellhead assembly being attached to the top of the casing.Recently, methods and apparatus have been developed for drilling andcompleting wells wherein both the well casinghead, and subsequently thewellhead assembly and easing closure device, are located underwater at adepth sufiicient to allow ships to pass over them. Preferably, thecasinghead and wellhead closure assemblies are located close to theocean floor. In order to install well drilling equipment underwater atdepths greater than the shallow depth at which a diver can easilyoperate, it has 'been necessary to design entirely new equipment forthis purpose.

Wells drilled in deep water are generally drilled from vessels ofvarying designs commonly known as drilling barges, vessels or platforms.Deep water wells are generally drilled by one of two methods. In onemethod, the string of drill pipe extends downwardly from the drillingvessel to the drilling wellhead assembly, on the ocean floor, which isclosed at the top :by a circulation head with a flexible hose runningfrom the circulation head back to the surface and to the drilling vesselso that drilling fluid may be circulated down the drill pipe, throughthe drill bit, and thence upwardly along the outside of the drill pipe,out the circulation head and up the flexible hose to the vessel again.In a second method, a large-diameter pipe known as a marine conductorpipe is put together and arranged to extend from the drilling wellheadassembly near the ocean floor to the vessel on the surface of the water.In the latter method, the drill pipe rotates within the conductor pipewith drilling fluid being circulated down through the drill pipe,through the bit at the bottom thereof, up the outside of the drill pipeand thence upwardly through the annular space between the conductor pipeand the drill pipe, returning to the barge in the conventional way. Thepresent invention is concerned with apparatus to be used in the secondmethod described hereinabove.

One of the problems in drilling underwater wells from floating vesselsis that of providing suitable means for suspending and/or supporting alarge-diameter marine conductor pipe and auxiliary smaller-diameterequipment or well-control pipes in the water beneath the drilling vesselwhile the lower ends thereof are secured to a wellhead assemblypositioned near the ocean floor. A further problem is encountered attimes when drilling at olfshore locations due to the possibility of aviolent storm which necessitates moving the drilling vessel away fromthe well being drilled or having it moved away by abnormal wind and waveaction. In the cases where the vessel has to be moved or is liable to bemoved, it is necessary to quickly disconnect the marine conductor andauxiliary lines from the drilling wellhead assembly near the ocean floorand withdraw them to the vessel prior to the vessel moving oif location.

Summary 0/ the invention It is therefore a primary object of the presentinvention to provide a marine conductor pipe assembly which can bequickly disconnected from a wellhead drilling assembly at the oceanfloor while control of the well being drilled is maintained by suitableblowout equipment left on the ocean floor.

Another object of the present invention is to provide a marine conductorpipe assembly of rugged design which can be built in sections smallenough to be handled easily on a drilling vessel while being providedwith means for connecting the various sections together easily andquickly.

A further object of the present invention is to provide means on thesectionalized marine conductor pipe assem bly whereby smaller-diameterauxiliary pipes extending from the vessel to the drilling equipment atthe ocean floor may be readily removed or replaced in case of emergencyor damage without pulling the marine conductor pipe assembly back to thevessel.

These objects have been attained in the present invention by providingapparatus for carrying out operations with respect to an underwater wellincluding a marine conductor made up of individual large-diameter pipesections connecti-ble in an end-to-end manner. Each of the pipe sectionsincorporates integral track guide means which in a preferred formcomprises angle irons having one edge secured to the section to extendradially outwardly therefrom and defining a slot. The slots of thevarious sections are in substantial alignment with one another andcooperate with T-shaped guide means secured to small-diameter pipestrings to maintain the pipe strings in a substantially parallel spacedrelationship with respect to the marine conductor pipe sections.Disconnect couplings are provided to releasably secure the pipe stringsand the marine conductor to an underwater wellhead assembly.

These and other objects of this invention will be understood from thefollowing description taken with reference to the drawing, wherein:

FIGURE 1 is a diagrammatic view taken in longitudinal projectionillustrating a floating drilling vessel positioned at the surface of theocean with an underwater wellhead assembly positioned on the oceanfloor;

FIGURES 2A and 2B are longitudinal views adapted to be arrangedend-to-end to show enlarged detail sections of the marine conductor pipeassembly of the present invention as it is positioned on a wellhead atthe ocean floor;

FIGURE 3 is an enlarged cross-section view of the marine conductor pipeassembly shown in FIGURE 2B taken across cut lines 3-3;

FIGURE 4 is a enlarged cross-sectional view of the marine conductor pipeassembly taken along cut lines 4-4 of FIGURE 3;

FIGURE 5 is an enlarged cross-sectional longitudinal view showing inenlarged detail the manner in which as illustrated, floating at thesurface of a body of Water 12 and being substantially fixedly positionedover a preselected drilling location by suitable barge-positioning meansor by being anchored to the ocean floor 13 by suitable anchors (notshown) connected to the anchor lines 14 and 15. Equipment of this typemay be used when carrying on well drilling operations in water depthsvarying from about 100 to 1500 feet or more. The drilling vessel isequipped with a suitable derrick 16 as well as other auxiliary equipmentneeded during the drilling of a well such as a hoist system 17, rotarytable 18, etc. The derrick 16 may be positioned over a drilling slot orwell which extends vertically through the vessel in a conventionalmanner. When using the equipment of the present invention, the slot ofthe vessel may be centrally located or extend in from one edge. However,drilling operations may be carried out over the deck of the vessel whichis cantilevered out over one end. Additionally, it is to be understoodthat the equipment of the present invention may be also used whendrilling a well from any suitable operational base positioned above thesurface of the water, such, for example, as from a drilling barge havinglegs extending to the ocean floor or from a platform permanentlypositioned on the ocean floor.

A typical underwater well head structure is illustrated in FIGURES l and2A as comprising a base member 21 which is positioned on the ocean floor13 and is fixedly secured to a conductor pipe or a large-diameter wellcasing 22 by means of a *ball-and-socket joint 23. During drillingoperations a drilling wellhead assembly is removably secured to the topof a foundation pile 24 which in turn is secured to the top of theball-and-socket joint 23. In the wellhead structure illustrated, thedrilling wellhead is secured to the top of a casinghead 25 which in turnis mounted at the top of the foundation pile 24. The combined casing 22,foundation pile 24 and casinghead 25 form a continuous tubular member orpipe extending up from the ocean floor through which drilling operationsare conducted.

The drilling wellhead assembly illustrated includes a detachablewellhead connector or drilling bonnet 27 of any type well known in theart. Fixedly secured above the casinghead 25 is a ram-type blowoutpreventer unit 28, a bag-type blowout preventer unit 29, a flexiblejoint 30, a remotely-operable quick-disconnect coupling and sealingapparatus 31, and a sectionalized marine conductor pipe assembly 32(FIGURE 1) extending to the vessel 11 at the surface.

As shown in FIGURE 23, the marine conductor pipe assembly consists of amarine conductor pipe 33 having an enlarged telescoping section 34 intowhich the upper end section 35 of the marine conductor pipe is arrangedfor sliding vertical movement, thus compensating for rise and fall ofthe vessel with wave action or tides. Near the upper end of the uppertelescoping section 35 is a discharge port 36 which communicates theinternal bore of the marine conductor pipe assembly 32 with the drillingfluid circulatory system. The usual flow of drilling fluid is throughthe drill string bore down to the drilling bit where the earth cuttingsare washed up and suspended and then circulated up the annulus betweenthe drill string and the inner wall of the marine conductor pipe anddischarged through the port 36 into a sump reservoir.

The upper end of the telescoping pipe section 35 may be secured to thedrilling vessel 11 in any suitable manner, as by cables 47 and 48. Theupper end of the marine conductor pipe assembly below the uppertelescoping section 35 is supported from the vessel by means of cables49 and 50 which extend to any suitable type of constant tension hoistmeans 51 and 52 which are mounted on the vessel 11.

The sections of marine conductor pipe below the telescoping section 34are joined end-to-end by any suitable type of coupling. One suchsuitable type of coupling, for example, is illustrated in FIGURES 3 and4 wherein one section 33 of marine conductor pipe is provided with themale section 41 of a stab-type fitting having conical recesses 43 formedtherein for receiving the locking bolts 44 carried by the female section42 of the coupling provided on the end of the adjacent section 33a ofmarine conductor pipe. It is apparent that the bolts 44 are of a formthat may be turned by a diver with a wrench or by an underwater robot.

Also provided on each section of marine conductor pipe are track guidemeans, such track guide means being designated by reference numeral 53with respect to pipe section 33 and by reference numeral 53a withrespect to pipe section 33a. Track guide means 53 and 53a have slots 54and 54a extending the entire length thereof to receive legs 56 and 56aof T-shaped pipe guide means 55 and 55a respectively. The T-guide legs56 and 56a are secured to sleeves 58 and 58a respectively whichconcentrically receive small-diameter pipe strings 39 and 40, which, inthis case, for example, may be choke and kill lines.

The T-guides 55 and 55a and guide tracks 53 and 53a cooperate to securethe choke and kill pipe strings 39 and 40 radially to the marineconductor pipe 33 but permit them to be installed or withdrawnindependently of said marine conductor pipe. Preferably sleeves 58 and58a are rotatively positioned on at least one of the associated pipestrings and held axially with respect thereto by means of collars, suchas collars 59 and 59a that are secured to said pipe by Welding, forexample. This arrangement is illustrated with respect to pipe string 39in FIGURES 3 and 4.

The rotary relationship between each sleeve member 58 and 58a and itsrespective pipe 39 allows each T-guide 55a to be aligned with theforegoing T-guide 55 and the guide track slots 54 and 54a subsequent tothe addition of each respective section of pipe which compositely formthe pipe string 39 to permit free running along the entire length of themarine conductor pipe in the cooperating guide tracks. If desired,however, one or both of the pipe strings may have the T-shaped pipeguide means 55 and 55a rigidly secured thereto as by welding such as isshown with respect to pipe string 40 in FIGURES 3 and 4.

It is pointed out that the guide tracks 53 and 53a extend radially outfrom the marine conductor pipe 33 a suflicient distance to allow theT-guides 55 and 55a to unobstructively pass the outermost radialshoulder of end couplings 42. The bolts 44 are in the position shown byFIGURE 4 for purposes of illustrative clarity only and are in factangularly spaced around the circumference of the couplings 42 so as toleave an unobstructed longitudinal path for the passage of the T-guides.

Guide tracks 53 and 53a may be constructed of continuous or intermittentlengths of two angle irons, each having one edge secured, as by welding,to the outer surface of the marine conductor pipes 33 and 33a betweenthe end couplings 41-42. The other edges of the angle irons are spaced,each oppositely facing the other, to form the slots 54 and 54a throughwhich the legs 56 and 56a of the T-guides 55 and 55a, respectively mayextend. Alignment plates 62 and 62a may be provided proximately of thetop and bottom ends of the guide tracks to hold the outer radial face ofthe T-guides snugly against the inner radial face of the guide tracks 53and 53a. As may be observed from FIGURE 4, the longitudinally oppositeends of alignment plates 62 and 62a taper away from the middle shoeportion of same to funnel the T-guides into the unobstructed passageportion between the alignment plates and the guide tracks.

Each angle iron is braced along its length by gussets such as gussets57a (FIGURE 3). In the case of intermittently spaced guide tracks, thespacings between longitudinally adjacent tracks 53 and 5311 should berelative to the longitudinalspacing between the T-guides so that asubstantial portion of the length of the auxiliary lines is supported bythe guide tracks at any axial position of said auxiliary lines. Ingeneral, the length of the individual T-guides should be greater thanthe length of the individual guide tracks 53, 530.

Although the guide tracks have been described as being connecteddirectly to the outer surface of the marine conductor pipe, it is to beunderstood that they may also be secured to the outer surface ofbuoyancy tanks which may surround and jacket each marine conductor pipesection. Moreover, it should also be understood that the relationshipbetween the guide tracks and the T-guide may be reversed with theT-guide mounted on the marine conductor pipe and the guide trackssecured to the auxiliary pipes 39 and 40.

The lower ends of the auxiliary lines 39 and 40 are provided withquick-disconnect couplings 63 and 64 (FIG- URE 2A). One form of aquick-disconnect coupling for use at the lower end of the auxilary lines39 and 40 is shown in FIGURE 5 as comprising a housing 78 in whichauxiliary pipe 39 can be stabbed. The pipe 39 is provided with seals 79and 80 above and below discharge ports 81 in the side wall of the pipeand annular passage 82 is provided in the housing 78 and around theports 81 with a discharge of fluid passing port 83 and thence downwardlyto the flexible line 39a (FIGURE 2A). The lower end of the pipe 39(FIGURE 5) is closed by a plug 84. A shoulder 86 is provided on thelower end of the housing 78 and is adapted to be engaged by spring-typelatching fingers 87. The upper beveled surface 88 of each latchingfinger 87 is flatter than the beveled surface 89 thereof, thus allowingthe latching device to be stabbed and locked in place with only a 500pound pressure, for example, while, say, a 2000-pound pull is needed topull it out of its latched position.

To insure proper alignment of the lower ends of auxiliary lines 39 and40 with the receptacles of quick-disconnect couplings 63 and 64,respectively, guide tubes 104 and 105 having funnel shaped upper endsare secured to the outer sleeve portion 89 of the coupling and sealingapparatus 31. The guide tubes are secured to the coupling 31 in coaxialalignment with the quick-connect couplings. The guide tubes are also inradial alignment with the auxiliary conduits 39 and 40 when secured totheir respective guide tracks 53a and 53. Since the outside diameter ofthe coupling 31 may be larger than that of the marine conductor pipefemale coupling sections 42, however, it may be necessary to provide thelower sections of auxiliary lines 39 and 40 with radially extendingdog-legs 45 and 46, respectively, to accommodate the radial dimensiondifferential between auxiliary line axis and the axis ofquick-disconnect couplings 63 and 64.

In the event that a flexible joint is employed in the drilling wellheadassembly, it is necessary that the portions of the auxiliary conduits39a and 40a opposite the flexible joint 30 be also flexible in order toprevent rupturing the lines. Thus, the conduits 39a and 40a may be madeof flexible hose of any suitable type. Below the flexible joint 30(FIGURE 2A) the flexible conduit 39a becomes a rigid conduit 39b, againwhich is preferably provided with a valve 65 which may be remotelyoperated either electrically or hydraulically or may be operated bymeans of an underwater robot.

If the conduit 39b is merely to be used as a choke or kill line for thedrilling wellhead assembly, it terminates by entering the blowoutpreventer 28 at flange 66 at a point below the lower set of rams of theblowout preventer. If, in addition, the conduit 39b is to be used as acement bypass line so as to allow cement return from the well to bypassstrings of casing already seated in the casinghead 25, the conduit 3%terminates at flange 67 and is provided with a valve 68 which is adaptedto be operated in a manner similar to valve 65.

The coupling and sealing apparatus 31 (FIGURE 6) between the lower endof the marine conductor pipe assembly 32 and the upper end of theflexible joint 30 comprises an outer sleeve 89 secured by bolts, notshown for clarity, to a flange on the lower end of the marine conductorpipe assembly. In closely fitting concentric relationship with theinternal bore 90 of the sleeve 89 is a mandrel 91 secured by bolts, notshown for clarity, to a flange on the upper end of the flexible joint30. When in place, the mandrel 91 is locked to the sleeve 89 by aplurality of latching members 93 which are held in interference fit in alatching recess 92 around the mandrel 91 by a locking ring 94. Thelocking ring is reciprocated from release to holding positions byseveral piston actuated rods 95 secured to the locking ring around theperiphery thereof. When hydraulic pressure is applied to the lockingcylinder 96 via conduit 99, pressure is applied to the face of a pistonto wedge the locking ring against the outer shoulder of the latchingmembers 93. When it is desired to release the mandrel 91, fluid pressureis applied to the rod side of the locking pistons via conduit 103 towithdraw the locking ring 94 to the release position where radicalclearance is allowed between beveled edges 97 and 98 of latching member93 and the locking ring 98, respectively. This radial clearance allowsthe latching member 93 to move radially out of latching recess 92,thereby freeing the mandrel 91 for axial movement relative to the sleeve89 so that the marine conductor pipe above the flexible joint 30 can bepulled away and disconnected from the drilling wellhead assembly in anemergency.

When in the locked, drilling position, the annular space between themandrel 91 and the sleeve 89 is sealed in a fluid-tight manner by member101. Sealing pressure is applied to the chamber 102 extendingperipherially around the sealing member 101 between same and a sectionof the sleeve 89. The sealing pressure is applied through a spur conduit100 in communication with the locking pressure conduit 99.

It is to be understood that all of the various components of thewellhead drilling assembly may be remotely actuable, as by beingoperated by hydraulic pressure lines extending from the vessel at thesurface. In the arrangement shown in FIGURES 2A and 2B, hydraulic hosesextend downwardly from the vessel in the form of a bundle of hoses 70which terminate at the mounting flange 74 (FIGURE 6). Secured to themounting flanges 74 and 75 are respective coupling elements ofconventional selfsealing, quick-connect hose couplings 72. Eachindividual hose 71 having a work function below the marine conductorpipe coupling 31 is provided with a coupling unit 72. Orientingconnector 73 assures proper circumferential alignment of the male andfemale elements of the couplings 72 to prevent damage thereto by slightangular misalignments between the mandrel 91 and the sleeve 89.

It may therefore be seen that, by utilizing the present invention, amarine conductor pipe assembly may be quickly separated from thewellhead assembly when desirable or necessary without injury to the manyhydraulic pressure conductor lines necessary to perform the functions ofthe wellhead assembly. Furthermore, with the present invention, themarine conductor pipe assembly may be operatively rejoined with thewellhead assembly with the greatest of expedition, most control linesbeing connected simultaneously with the connection of the marineconductor pipe. In addition to the foregoing advantages, the auxiliarysmall-diameter pipes for the choke and kill conduits 39 and 40 may beindependently withdrawn to the vessel, repaired and replaced in theevent of plugging or other damage rendering them inoperative.

I claim as my invention:

1. Apparatus for drilling, completing and working over an underwaterwell, said apparatus comprising:

operational platform means positioned above the surface of a body ofwater;

a well base positioned below the surface of the water and includingsubstantially vertical well base pipe means having a lower portionthereof fixedly anchored to the formation below said body of water and aportion extending upwardly above said formation;

marine conductor means comprising a marine conduc' tor pipe made up ofindividual large-diameter pipe sections connectible in an end-to-endrelationship, said marine conductor means connectible at its lower endto the upper end of said well base pipe means with the upper end of saidconductor pipe extending above the surface of the water in the vicinityof said operational platform means;

track guide means longitudinally secured to said marine conductor meanson the outside thereof with at least a portion of said track guide meansbeing operatively associated with each of said individual,large-diameter pipe sections;

auxiliary conduit means extending longitudinally parallel with saidmarine conductor means and closely adjacent thereto;

a plurality of pipe guide means secured to said auxiliary conduit meansand cooperatively engageable with said track guide means, at least someof said pipe guide means being rotatably disposed on said auxiliaryconduit means;

one of said guide means having slot means for longitudinally slidablyreceiving cooperating means secured to the other of said guide means.

2. The apparatus of claim 1 wherein said apparatus includes a drillingwellhead assembly secured to said upper portion of said well base pipemeans.

3. The apparatus of claim 2 wherein said drilling wellhead assemblycomprises:

blowout preventer means;

a disconnect coupling section secured above said blowout preventer meanswhich is adapted to be detachably secured to the lower end of saidmarine conductor pipe; and

auxiliary conduit disconnect coupling means carried on the outside ofsaid drilling wellhead assembly and in communication with the interiorthereof, said auxiliary conduit means being connectable at the lower endthereof to said auxiliary conduit disconnect coupling means.

4. The apparatus of claim 3 wherein said auxiliary conduit meanscompirse individual choke and kill pipelines and wherein said choke and'kill line disconnect coupling means comprise indivdual quick dsconnectcouplngs at the bottom of said choke and kill pipelines.

5. The apparatus according to claim 1, wherein said track guide meansincorporates said slot means and said pipe guide means comprises aplurality of T-shaped guides adapted to cooperate with said slot means.

References Cited UNITED STATES PATENTS 2,984,308 5/1961 Bauer et al. -73,189,098 6/1965 Haeber 175-7 X 3,215,454 11/1965 Hayes 166-0.5 X3,221,817 12/1965 De Vries et al. 166-05 3,258,928 7/ 1966 Broadway etal. 1660.5 X 3,280,908 10/1966 Todd 285-48 X 3,330,340 7/ 1967 Hayes etal. 166-0.6 3,332,484 7/1967 Watkins 166--0.6 3,333,870 8/1967 Watkins285-18 CHARLES E. OCONNELL, Primary Examiner.

I. A. CALVERT, Assistant Examiner.

U.S. Cl. X.R.

